Beer-breaths beware. A new concept car with breathalyzer-like detection systems may provide even greater traction for Japanese efforts to keep impaired drivers off the road. Nissan?s alcohol-detection sensors check odor, sweat and driver awareness, issuing a voice alert from the navigation system and locking up the ignition if necessary.

Odor sensors on the driver and passenger seats read alcohol levels, while a detector in the gear-shift knob measures the perspiration of the driver?s palm when starting the car.

Other carmakers with detection systems include Sweden?s Volvo, which has developed technology in which drivers blow into a measuring unit in the seat belt before an engine can start.

But Nissan?s car includes a mounted camera that monitors alertness by eye scan, ringing bells and issuing a voice message in Japanese or English if a driver should pull over and rest.